Britain's 6 million unpaid carers who look after relatives or dependants are bamboozled by "incomprehensible" official guidance on benefits, MPs say today. Only about 900,000 people receive allowances, partly because regulations are "unnecessarily complex" and inadequately advertised, the Commons public accounts committee suggests. The study notes that £2bn a year is given out in benefits to carers, while their commitment saves the Treasury around £23bn in health and social work bills. It adds that jobcentres do not provide enough help to carers seeking part-time work.

"Benefits for carers are unnecessarily complex and cause confusion," the report states. "About a fifth of carers who receive benefits have difficulties with some aspect of the application process."

Simply understanding information provided by the Department of Work and Pensions (DWP) is a problem for many. Some carers have to apply for payments they know they are not eligible for in order to qualify for supplementary smaller supports. "The [DWP's] communications with customers can be lengthy and difficult to understand," the committee says. One letter sent out to an applicant and seen by the committee began: "You are entitled to £48.65 from 21/05/2007. We cannot pay you from 21/05/2007 …"

Jobcentres do not provide sufficient help to carers seeking part-time work, the committee says. A sum of £38m put aside for that purpose may not all have been spent last year, the committee fears, because some of it may have been diverted to cope with the surge in unemployment.

The committee calls for supplementary payments to be made more easily accessible and bemoans the fact that despite previous criticisms official communications remain "incomprehensible".

Further research is needed to establish what proportion of the eligible population take up allowances, the committee recommends. Publicity campaigns should be improved, targeting ethnic minorities, different age groups and every part of the country.

The chairman of the committee, Edward Leigh, said: "Millions of people devote a large part of their time, often for many years, to caring for family or friends who are ill or disabled. But the value of the service that these unpaid carers provide to society is not reflected in the quality of the DWP's arrangements for providing them with financial and other support.

"Carers who apply for benefits should not have to wade through official written guidance and communications which can range from the hard to understand to the downright incomprehensible. And they should not have to be jumping through unnecessary hoops to apply for benefits and allowances.

"[Jobcentre] staff work with a rigid template which does not help them to assess and respond to the inevitable complexity of carers' circumstances and availability for work. "